What you can do is report to Airbnb that they guest agreed to change their review (the can't) in exchange for a full refund. Do it by phone hitting the report button is unlikely to do much.
It sounds like you have set up your listing without fully understanding how Airbnb works if you think a guest can change their review.
Do read up on how host and guest reviews work on the Airbnb Help Centre and while you are there read up on the other Q and As to help you better understand how the platform works.
By the way if you are offering two bedroom apartments you should provide two sofas, not one sofa and you rather uncomfortable looking dining room chairs. Would you really like to sit on those of an evening, say to watch a movie or relax with friends?